1 /* (c) 2007,2008 Andrei Nigmatulin */
2
3 #include "fpm_config.h"
4
5 #include <signal.h>
6 #include <stdio.h>
7 #include <sys/types.h>
8 #include <sys/socket.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <fcntl.h>
12 #include <unistd.h>
13 #include <errno.h>
14
15 #include "fpm.h"
16 #include "fpm_signals.h"
17 #include "fpm_sockets.h"
18 #include "fpm_php.h"
19 #include "zlog.h"
20
21 static int sp[2];
22 static sigset_t block_sigset;
23 static sigset_t child_block_sigset;
24
25 const char *fpm_signal_names[NSIG + 1] = {
26 #ifdef SIGHUP
27 [SIGHUP] = "SIGHUP",
28 #endif
29 #ifdef SIGINT
30 [SIGINT] = "SIGINT",
31 #endif
32 #ifdef SIGQUIT
33 [SIGQUIT] = "SIGQUIT",
34 #endif
35 #ifdef SIGILL
36 [SIGILL] = "SIGILL",
37 #endif
38 #ifdef SIGTRAP
39 [SIGTRAP] = "SIGTRAP",
40 #endif
41 #ifdef SIGABRT
42 [SIGABRT] = "SIGABRT",
43 #endif
44 #ifdef SIGEMT
45 [SIGEMT] = "SIGEMT",
46 #endif
47 #ifdef SIGBUS
48 [SIGBUS] = "SIGBUS",
49 #endif
50 #ifdef SIGFPE
51 [SIGFPE] = "SIGFPE",
52 #endif
53 #ifdef SIGKILL
54 [SIGKILL] = "SIGKILL",
55 #endif
56 #ifdef SIGUSR1
57 [SIGUSR1] = "SIGUSR1",
58 #endif
59 #ifdef SIGSEGV
60 [SIGSEGV] = "SIGSEGV",
61 #endif
62 #ifdef SIGUSR2
63 [SIGUSR2] = "SIGUSR2",
64 #endif
65 #ifdef SIGPIPE
66 [SIGPIPE] = "SIGPIPE",
67 #endif
68 #ifdef SIGALRM
69 [SIGALRM] = "SIGALRM",
70 #endif
71 #ifdef SIGTERM
72 [SIGTERM] = "SIGTERM",
73 #endif
74 #ifdef SIGCHLD
75 [SIGCHLD] = "SIGCHLD",
76 #endif
77 #ifdef SIGCONT
78 [SIGCONT] = "SIGCONT",
79 #endif
80 #ifdef SIGSTOP
81 [SIGSTOP] = "SIGSTOP",
82 #endif
83 #ifdef SIGTSTP
84 [SIGTSTP] = "SIGTSTP",
85 #endif
86 #ifdef SIGTTIN
87 [SIGTTIN] = "SIGTTIN",
88 #endif
89 #ifdef SIGTTOU
90 [SIGTTOU] = "SIGTTOU",
91 #endif
92 #ifdef SIGURG
93 [SIGURG] = "SIGURG",
94 #endif
95 #ifdef SIGXCPU
96 [SIGXCPU] = "SIGXCPU",
97 #endif
98 #ifdef SIGXFSZ
99 [SIGXFSZ] = "SIGXFSZ",
100 #endif
101 #ifdef SIGVTALRM
102 [SIGVTALRM] = "SIGVTALRM",
103 #endif
104 #ifdef SIGPROF
105 [SIGPROF] = "SIGPROF",
106 #endif
107 #ifdef SIGWINCH
108 [SIGWINCH] = "SIGWINCH",
109 #endif
110 #ifdef SIGINFO
111 [SIGINFO] = "SIGINFO",
112 #endif
113 #ifdef SIGIO
114 [SIGIO] = "SIGIO",
115 #endif
116 #ifdef SIGPWR
117 [SIGPWR] = "SIGPWR",
118 #endif
119 #ifdef SIGSYS
120 [SIGSYS] = "SIGSYS",
121 #endif
122 #ifdef SIGWAITING
123 [SIGWAITING] = "SIGWAITING",
124 #endif
125 #ifdef SIGLWP
126 [SIGLWP] = "SIGLWP",
127 #endif
128 #ifdef SIGFREEZE
129 [SIGFREEZE] = "SIGFREEZE",
130 #endif
131 #ifdef SIGTHAW
132 [SIGTHAW] = "SIGTHAW",
133 #endif
134 #ifdef SIGCANCEL
135 [SIGCANCEL] = "SIGCANCEL",
136 #endif
137 #ifdef SIGLOST
138 [SIGLOST] = "SIGLOST",
139 #endif
140 };
141
sig_soft_quit(int signo)142 static void sig_soft_quit(int signo) /* {{{ */
143 {
144 int saved_errno = errno;
145
146 /* closing fastcgi listening socket will force fcgi_accept() exit immediately */
147 close(fpm_globals.listening_socket);
148 if (0 > socket(AF_UNIX, SOCK_STREAM, 0)) {
149 zlog(ZLOG_WARNING, "failed to create a new socket");
150 }
151 fpm_php_soft_quit();
152 errno = saved_errno;
153 }
154 /* }}} */
155
sig_handler(int signo)156 static void sig_handler(int signo) /* {{{ */
157 {
158 static const char sig_chars[NSIG + 1] = {
159 [SIGTERM] = 'T',
160 [SIGINT] = 'I',
161 [SIGUSR1] = '1',
162 [SIGUSR2] = '2',
163 [SIGQUIT] = 'Q',
164 [SIGCHLD] = 'C'
165 };
166 char s;
167 int saved_errno;
168
169 if (fpm_globals.parent_pid != getpid()) {
170 /* Avoid using of signal handlers from the master process in a worker
171 before the child sets up its own signal handlers.
172 Normally it is prevented by the sigprocmask() calls
173 around fork(). This execution branch is a last resort trap
174 that has no protection against #76601. */
175 return;
176 }
177
178 saved_errno = errno;
179 s = sig_chars[signo];
180 zend_quiet_write(sp[1], &s, sizeof(s));
181 errno = saved_errno;
182 }
183 /* }}} */
184
fpm_signals_init_main()185 int fpm_signals_init_main() /* {{{ */
186 {
187 struct sigaction act;
188
189 if (0 > socketpair(AF_UNIX, SOCK_STREAM, 0, sp)) {
190 zlog(ZLOG_SYSERROR, "failed to init signals: socketpair()");
191 return -1;
192 }
193
194 if (0 > fd_set_blocked(sp[0], 0) || 0 > fd_set_blocked(sp[1], 0)) {
195 zlog(ZLOG_SYSERROR, "failed to init signals: fd_set_blocked()");
196 return -1;
197 }
198
199 if (0 > fcntl(sp[0], F_SETFD, FD_CLOEXEC) || 0 > fcntl(sp[1], F_SETFD, FD_CLOEXEC)) {
200 zlog(ZLOG_SYSERROR, "falied to init signals: fcntl(F_SETFD, FD_CLOEXEC)");
201 return -1;
202 }
203
204 memset(&act, 0, sizeof(act));
205 act.sa_handler = sig_handler;
206 sigfillset(&act.sa_mask);
207
208 if (0 > sigaction(SIGTERM, &act, 0) ||
209 0 > sigaction(SIGINT, &act, 0) ||
210 0 > sigaction(SIGUSR1, &act, 0) ||
211 0 > sigaction(SIGUSR2, &act, 0) ||
212 0 > sigaction(SIGCHLD, &act, 0) ||
213 0 > sigaction(SIGQUIT, &act, 0)) {
214
215 zlog(ZLOG_SYSERROR, "failed to init signals: sigaction()");
216 return -1;
217 }
218
219 zlog(ZLOG_DEBUG, "Unblocking all signals");
220 if (0 > fpm_signals_unblock()) {
221 return -1;
222 }
223 return 0;
224 }
225 /* }}} */
226
fpm_signals_init_child()227 int fpm_signals_init_child() /* {{{ */
228 {
229 struct sigaction act, act_dfl;
230
231 memset(&act, 0, sizeof(act));
232 memset(&act_dfl, 0, sizeof(act_dfl));
233
234 act.sa_handler = &sig_soft_quit;
235 act.sa_flags |= SA_RESTART;
236
237 act_dfl.sa_handler = SIG_DFL;
238
239 close(sp[0]);
240 close(sp[1]);
241
242 if (0 > sigaction(SIGTERM, &act_dfl, 0) ||
243 0 > sigaction(SIGINT, &act_dfl, 0) ||
244 0 > sigaction(SIGUSR1, &act_dfl, 0) ||
245 0 > sigaction(SIGUSR2, &act_dfl, 0) ||
246 0 > sigaction(SIGCHLD, &act_dfl, 0) ||
247 0 > sigaction(SIGQUIT, &act, 0)) {
248
249 zlog(ZLOG_SYSERROR, "failed to init child signals: sigaction()");
250 return -1;
251 }
252
253 zend_signal_init();
254
255 if (0 > fpm_signals_unblock()) {
256 return -1;
257 }
258 return 0;
259 }
260 /* }}} */
261
fpm_signals_get_fd()262 int fpm_signals_get_fd() /* {{{ */
263 {
264 return sp[0];
265 }
266 /* }}} */
267
fpm_signals_init_mask()268 int fpm_signals_init_mask() /* {{{ */
269 {
270 /* Subset of signals from fpm_signals_init_main() and fpm_got_signal()
271 blocked to avoid unexpected death during early init
272 or during reload just after execvp() or fork */
273 int init_signal_array[] = { SIGUSR1, SIGUSR2, SIGCHLD };
274 size_t size = sizeof(init_signal_array)/sizeof(init_signal_array[0]);
275 size_t i = 0;
276 if (0 > sigemptyset(&block_sigset) ||
277 0 > sigemptyset(&child_block_sigset)) {
278 zlog(ZLOG_SYSERROR, "failed to prepare signal block mask: sigemptyset()");
279 return -1;
280 }
281 for (i = 0; i < size; ++i) {
282 int sig_i = init_signal_array[i];
283 if (0 > sigaddset(&block_sigset, sig_i) ||
284 0 > sigaddset(&child_block_sigset, sig_i)) {
285 if (sig_i <= NSIG && fpm_signal_names[sig_i] != NULL) {
286 zlog(ZLOG_SYSERROR, "failed to prepare signal block mask: sigaddset(%s)",
287 fpm_signal_names[sig_i]);
288 } else {
289 zlog(ZLOG_SYSERROR, "failed to prepare signal block mask: sigaddset(%d)", sig_i);
290 }
291 return -1;
292 }
293 }
294 if (0 > sigaddset(&child_block_sigset, SIGTERM) ||
295 0 > sigaddset(&child_block_sigset, SIGQUIT)) {
296 zlog(ZLOG_SYSERROR, "failed to prepare child signal block mask: sigaddset()");
297 return -1;
298 }
299 return 0;
300 }
301 /* }}} */
302
fpm_signals_block()303 int fpm_signals_block() /* {{{ */
304 {
305 if (0 > sigprocmask(SIG_BLOCK, &block_sigset, NULL)) {
306 zlog(ZLOG_SYSERROR, "failed to block signals");
307 return -1;
308 }
309 return 0;
310 }
311 /* }}} */
312
fpm_signals_child_block()313 int fpm_signals_child_block() /* {{{ */
314 {
315 if (0 > sigprocmask(SIG_BLOCK, &child_block_sigset, NULL)) {
316 zlog(ZLOG_SYSERROR, "failed to block child signals");
317 return -1;
318 }
319 return 0;
320 }
321 /* }}} */
322
fpm_signals_unblock()323 int fpm_signals_unblock() /* {{{ */
324 {
325 /* Ensure that during reload after upgrade all signals are unblocked.
326 block_sigset could have different value before execve() */
327 sigset_t all_signals;
328 sigfillset(&all_signals);
329 if (0 > sigprocmask(SIG_UNBLOCK, &all_signals, NULL)) {
330 zlog(ZLOG_SYSERROR, "failed to unblock signals");
331 return -1;
332 }
333 return 0;
334 }
335 /* }}} */
336
